The present invention relates to remote tracking of objects and in particular to remote tracking and accounting of records, equipment, and any movable object.
Present day businesses expend great amounts of financial and personal resources in attempting to locate and manage objects, including records, equipment, and people. However, present day recordkeeping systems are ineffective at locating these objects.
Many objects must be located quickly to save loss of life and property. For instance, in the hospital setting, patients who are critically ill can best be treated when their physician has their complete medical record in hand. Oftentimes, their records are not available to the treating physician because they have been lost or misplaced. The cost and time dedicated to finding them becomes expensive and potentially life-threatening.
When conditions are not life-threatening, losses are incurred by the health system as a whole, since extra tests are given, delays in diagnosis occur, and major delays in billing result because, for periods of time, these records are lost and cannot be found.
One attempt at tracking file folders, for example, is given in U.S. Pat. No. 5,287,414 whereby an optical scanner mounted to the file drawer is used to detect files stored in the filing cabinet so that, upon opening or closing the filing cabinet drawer, all the files in that drawer are scanned. The scanned folders are logged as being located in that drawer by a computer system. A major drawback of this system is its inability to account for files unless they are located within a filing cabinet drawer.
Attempts at tracking materials and people have also been made, for example, in U.S. Pat. No. 5,363,425, whereby an identification badge containing a radio frequency transmitter is located across a telephone network by receiver units in or near telephone sets. However, this invention teaches the use of random transmissions from the identification badges, which is not applicable to systems containing a number of transmitters because of overlapping or xe2x80x9ccollidingxe2x80x9d of transmission bursts.
An attempt at tracking persons was made by an infrared active badge as described in the December 1993 Byte article xe2x80x9cTrack People With Active Badgesxe2x80x9d. This reference teaches the use of infrared transmitters because of their ready availability in television and video recorders and because the signals bounce off of walls which compensates for their directivity. However, the infrared technology disclosed is inadequate for applications where the transmitter is covered by a surface which blocks transmission of infrared light. This design also requires more receivers per installation due to the opacity of objects to infrared light.
Therefore, there is a need in the art for an inexpensive tracking system for a collection of objects which is capable of tracking a large number of objects. Such a tracking system must be able to track objects within an entire room or group of rooms and detect objects even if there is no clear optical path between the beacons and the detecting system. There is also a need for a low power, low cost beacon design to control the overall cost of the tracking system. Additionally, there is a need for a system having a minimal number of receivers to control the cost of the system and the invasiveness of the installation, and the receivers should have an effective means for transferring information to a central processor for processing location information.
The present invention solves the aforementioned problems and shortcomings of the existing art and solves other problems not listed above which will become apparent to those skilled in the art upon reading and understanding the present specification and claims.
The present invention is a multipurpose tracking system which is capable of tracking any movable object. For purposes of illustration, this discussion will center on one embodiment of the present invention which relates to the tracking of medical records using a plurality of transmitting tags (xe2x80x9ctagxe2x80x9ds) and one or more receiver base stations (xe2x80x9cRBSxe2x80x9ds). This embodiment reduces the problems associated with tracking of objects such as files, equipment or people by electrically tracking the records as they are moved about the hospital. Tracking is performed by transmitting tag specific identification and error correction information by each tag to one or more RBSs. Tag information is time stamped and transferred by the RBSs to a central processor which uses the tag information to locate a tag (and its attached file). Tags are located by associating a RBS site for each file in the system. An individual record locator or xe2x80x9csnifferxe2x80x9d is also taught which may be used to locate a record located in a large cell range.
In this embodiment the tags are assigned their own identification code as they are commissioned. Each tag transmits according to a specialized, error-compensated time-multiplex arrangement, which avoids overlap of transmissions, even for large numbers of transmitting tags. Tag timing inconsistencies are corrected by comparing each tag clock with an accurate system clock and the errors are compensated by an offset downloaded to the tag to correct for mistiming. A low power transmitter on each tag provides a long lifetime of each transmitter.
The geometries of the RBS reception ranges are critical, since these geometries determine the scope of each RBS site and the overlap of the sites is beneficial in detecting transition of the record from one RBS site to the next. If the reception ranges overlap, then the transition is continually recorded and the record location is never uncertain. Tailoring the RBS reception range geometries provides accurate tag location detection, even for varying room or hall geometries.
One embodiment of the present invention incorporates a tag programmer for programming the transmitting tags in the tracking system. Details of the tag programmer are also provided below.
Therefore, this embodiment of the present invention solves the deficiencies of the prior art enumerated above and other deficiencies by providing a multipurpose radio frequency tracking system. As mentioned above, other embodiments of the present invention are possible and limited variations will be discussed throughout the specification.